Association of Exposure to Indoor Air Pollutants and Respiratory Health Symptoms among Photocopy Workers in Bandar Baru Bangi, Selangor

Abstract

Introduction: Indoor air quality (IAQ) has a significant impact on individual well-being, particularly in photocopy industry workers who are exposed to high levels of contaminants. Improper IAQ is linked to various health issues including respiratory symptoms. This study aimed to determine the association between exposure to indoor air pollutants and respiratory health symptoms among photocopy workers in Bandar Baru Bangi, Selangor. Methods: A cross-sectional comparative study was conducted between exposed and control groups consisted of 76 employees who worked in photocopy premises and 76 employees who worked in offices. A set of questionnaires adapted from the American Thoracic Society was used to collect data on respiratory health symptoms, history of exposure, and socio-demographic background of the employees. Area monitoring was performed using various direct reading devices to measure UFP, PM2.5, PM10, CO, CO2, and TVOCs. Results: In all photocopy centers of exposed group, the mean of PM10 and PM2.5 were at 344.16 µg/m3 and 315.24 µg/m3 (p<0.001), which exceeded the acceptable limit of respirable particulates by ICOP at 150 µg/m3; UFP level at 9068.75 pt/cc (p<0.001); and TVOC at 2.32 ppm (p<0.001), below the limit of 3.0 ppm. High PM10 exposures was reported significantly associated with all respiratory symptoms at p<0.001 (cough OR=3.89 (95% CI=1.00–15.07); phlegm OR=4.82 (95% CI=1.19–14.60); wheezing OR=1.77 (95% CI=1.54–5.79); shortness of breath OR=2.13 (95% CI=0.82–5.55); chest tightness OR=0.37 (95% CI=0.14–0.98)); high PM2.5 exposure was significantly associated with all symptoms except for wheezing (cough at p<0.001, OR=6.71 (95% CI=1.41–32.00; phlegm at p<0.001, OR=5.15 (95% CI=1.41–32.00); shortness of breath at p<0.05, OR=2.13 (95% CI=0.85–5.32); and chest tightness at p<0.05, OR=0.37 (95% CI=0.15–0.95); meanwhile high exposure to UFP had significant relationships with shortness of breath at p<0.001, OR=0.66 (95% CI=0.27–1.64) and chest tightness at p<0.001, OR=1.51 (95% CI=0.61–3.74) among respondents. TVOC also had significant relationships with shortness of breath at p<0.001, OR=1.25, 95% CI=0.47–3.35 and chest tightness at p<0.001, OR=1.04, 95% CI=0.23–1.68. Results also showed that symptoms of cough, phlegm and wheezing were influenced by the PM10 and PM2.5 exposure at 49.4% (Nagelkerke R2= 0.494), 60.1% (Nagelkerke R2= 0.601) and 56.3% (Nagelkerke R2=0.563), respectively. However, there were no significant factors that influenced the symptom of shortness of breath and chest tightness among the respondents. Conclusion: This study concluded that exposure to indoor air pollutants increased the risk of respiratory health symptoms among photocopy workers. This study suggests that regular photocopy machine maintenance and daily workplace housekeeping is required, whereas the photocopy workers should be fully trained in terms of technical, health and safety aspects.